In view of numerous factors such as higher energy prices and environmental concerns, the production of value-added gaseous products from lower-fuel-value carbonaceous feedstocks, such as petroleum coke and coal, is receiving renewed attention. The catalytic gasification of such materials to produce methane and other value-added gases is disclosed, for example, in U.S. Pat. Nos. 3,828,474, 3,998,607, 4,057,512, 4,092,125, 4,094,650, 4,204,843, 4,468,231, 4,500,323, 4,541,841, 4,551,155, 4,558,027, 4,606,105, 4,617,027, 4,609,456, 5,017,282, 5,055,181, 6,187,465, 6,790,430, 6,894,183, 6,955,695, US2003/0167961A1, US2006/0265953A1, US2007/000177A1, US2007/083072A1, US2007/0277437A1 and GB1599932.
The process for the catalytic gasification of a carbonaceous material to synthetic natural gas requires the presence of steam to react with carbon either in the gas phase or on the surface of the carbonaceous material to generate methane and carbon dioxide. It has generally been contemplated to utilize coal-fired boilers to generate the required steam. Such methods have the disadvantages of requiring an additional fuel source for the boiler, while producing an exhaust comprising additional acid gases (e.g, carbon dioxide, sulfur dioxide, nitrous oxides), which must be treated and exhausted to the atmosphere or otherwise sequestered. As such, there exists a need in the art to develop apparatuses and processes for the catalytic gasification of carbonaceous materials to synthetic natural gas which more efficiently utilize fuels sources while decreasing the carbon footprint of the overall process.